Chucking device for lathes



0d. 14, 11952 M. o. TRUDEAU CHUCKING DEVICE FOR LATHES 5 Sheets-Sheet 1 Filed July 20, 1950 INVENTOR. MAX 0. TRUDE AU ATTORNEY M. O. TRUDEAU CHUCKING DEVICE FOR LATHES Get. 14, 1952 3 Sheets-Sheet 2 Filed July 20, 1950 INVENTOR.

TRUDEAU MAX 0.

ATTORNEY Oct. 14, 11952 M. o. TRUDEAU CHUCKING DEVICE FOR LATHES 5 Sheets-Sheet 3 JNVENTOR.

MAX 0. TRUDEAU 81 ATTORNEY Patented Oct. 14, 1952 2 siasns CHUCKING DEVICE non LATHES Max 0. Trudeau, Jackson Heights, N. Y., assignor to Morey Machinery 00., Inc., Astoria, L. L, N. Y., a corporation of New York Application July;20, 1950, Serial No. 174,858

12 Claims.

This invention relates to chucking devices for lathe's. It is particularly directed to a chucking device for chucking annular workpieces such as gear blanks and the like.

An object of the present invention is to provide an improved chucking device of the character described having means for clamping the work piece radially and laterally at the same time, to enable clamping across solid metal rather than exerting the total of the clamping force across the diameter of the work, thereby eliminating distortion.

A further object of this invention is to provide in a chucking device of the character described, a backing for the work piece to take the thrust of the lateral clamping force, said backing comprising arcuate members provided with serrations or teeth which act to clamp as well as rotate the work piece.

Yet a further object of this invention is to provide a chucking device of the character described comprising radially extending cams, a rotatably mounted clamping jaw adapted to be rotated by each cam, and a central operating cone movably axially to simultaneously move the cams for rotating the jaws into engagement with the work piece. 7

Yet a further object of this invention is to provide a chucking device of the character described including hydraulic means to act on the cams independently of each other for individually rotating the clamping jaws.

Still another object of this invention is to provide a chucking device of the character described comprising a chuck body attachable to the nose of a lathe spindle and rotatable therewith, a, plurality of radially movable members,

and clamping jaws associated with said radial members respectively, and pivotable about axes tangent to a common circle coaxial with the chuck body, each clamping jaw comprising an arm engageable with one radial member and a jaw engageable with a work piece, the arrange-- be easy to assemble, which shall be sure and positive in operation-and yet practical. and' ef-l ficient to a high degree in use.

Other objects of this invention will in part be obvious and in part hereinafter. pointed out.1' Q} The invention accordingly consists in the features of construction,lcombinations of elements, and arrangements of parts; which will -be, ex emplified in the construction hereinafter fde-.

scribed, and of whichthe scope of invention'wi be indicated in the following claims. In the accompanying. draw ings in which-,is' shown various illustrative embodiments of thisf invention, 4 L Fig. 1 is a coaxial cross-sectional view pf a1 chucking device, embodying. the invention and attached to the front end. of a lathe spindle; Fig. 2 is a front end view ofithe chucking device embodyingthe invention; I Fig. 3 is a cross-sectional view takerron' line 33 of Fig. 1; 1 Fig. 4 isa perspective vi'ew,of the operating cone; I Fig. 5 is a perspective view of one of the'radial cam members; and a Fig. 6 is a coaxial cross-sectional view, arms chucking device and lathe spindle embodying the. invention and illustrating a hydraulically oper ated modification of the invention. f 3 Referring now in detail to the drawingjlll designates a spindle of a lathe to the forward end or nose. of whichis attached a chucking device. ll, embodying the invention and con-. trolled by a draw bar I3 passing throughthe spindle. The spindle Ill may-be ofpusual con struction. It has acoaxial through opening l l At the forward end of the opening I4 is an en larged socket. IS. The spindle is provided adjacent its forward end with an outwardly ex tending annular flange 16. surrounding the forward end of the recess or enlarged socket I5 is an annular flange I! provided with a tapered outer surface l8. The chucking device It! comprises a chuck body 20. Said body 20 comprises an annular: outwardly extending flange 2| formed withthree equi-angularly spaced similar notches 22. Each notch 22 has a' flat bottom surface 23. The surfaces 23 are tangent to a common :circle. At the ends ofeach flat surface 23 are parallel end surfaces 24. Flange 2| hasa rearsurface 2-5 and a front surface 26, and an outer edge :21; Extending rearwardly from the annularfiange 2|. isan annular flange 21a having a. rear sur; face 28. The surface 29 ofthe spindle surrounds,

. the taper ed surface l8. The flange g1 chuck body. Each slot 34 has arear surface 31,

parallel side surface 38 and a frontsurfa'ce 39".

Extending outwardly and forwardly from'the':

flange 33 are web portions 4|. Extending forwardly from the annular flange ZI and on op-" posite sides of each slot 34 are a pair of parallel walls 42, the lower endsrof which are interconnected by-the web 4|. Each pair of parallelportions 42' have inner parallelspaced walls 43 disposed forwardly and above .wall'39 of the slot 34. Forwardly of the surface 43 .and spaced between the arms 42 is enlarged outwardly and forwardly curved surface 4'6 fromwhichi extends parallel surfaces .4|.' Thus the 'forward'ends 48 of the arms 42 are spaced from each other and are disposed parallel. to one another.

One of the arms -48 is formed witha through opening 49 and the otherarm is formed with a.through opening 49a formed with an internal shoulder 43b; The reduced portion of theopening.,49a is screw threaded. The outer ends of the openings :49," 49amay becounterbored as at 50. The space between the arms 48 may be designated by the numeral I. It will. be seen that the spaces 5I"are disposed radially 'outwardly'of the 'webs 4|... Each web 4| .has aniouter inclined surface 52,'as shown in Fig. 1 of the drawing, and a flat outer end surface 53.. Each web 4| has'a front end surface 54 which is in the plane of the forward end surface 55 of the arms 48. I

At the forward end of-each web 4| is an arcuateend groove 56 comprising a flat-inner surface 51 and .a part-cylindrical outer surface 58. The outer surfaces ofthe arms 42 are in'the cylindrical surface 21-of the flange 2|. 22. hence extend; longitudinally through the arms 42 as'wellas-through the flange 2 I. The portions ofithefflange 2|between the-sides of arms 42 are'formed with-pairs of parallel through bolt openings 60to receive bolts 6| screwed into screw threaded openings 62 in each flange I6 of the spindle;- The openings 60 are counterbored to receive heads ofthe bolts and said boltshence serveto fix the chuck body to the spindle.

It will be noted that the forward end of each web 4| is formed with three radial through screw threaded openings 54a. It will be noted furthermore'that the-flat bottom surface 23 of each notch 22 extends through the arms 42 from front to rear. The chuck body is formed with a pluralit'y-of screw threadedopenings 66 extending inwardly from saidsurfaces '23 for the purpose hereinafter appearing.

Disposed within theannula'r-groove is a face cover or annular plate I0 attached to the front end ofthe flange 33 by means of screws 'II', screwed into the threaded openings 36-.

Disposed within each arcuate groove 56 is a backjaw I2. Each back jaw is arcuate and contacts the surfaces 51; 58 of the web 4|. It is fixed to-the web by means of 'screws'13 passing through *suitable counterbored openings 14 in the back jaw and registering with the threaded The notchesopenings 54a. Each back jaw 12 is formed at its front with two sets of teeth or serrations T5. The teeth all extend or are inclined in the driving direction of the spindle. The spaces between the teeth are inclined forwardly and radially outwardly and the outer edges of the teeth are. preferably. curved, asshownimFig. 1 of the drawing.

Within each of the notches 22 is a rim cover 1! having an outer transversely curved surface 18 conforming to the outer curvature of surface 21. Said rim 1 cover has parallel longitudinal edges fitting within the surfaces 24 of the notch 22.1. Said cover is formed with counterbored vthroughppenings '19 to receive screws 80 which attach rim cover to the chuck body. The inner surface of each rim cover may be recessed as at.8|... Itwill be understood that each rim cover covers the spaces 5| and the slot 34 between each pair of parallel .arms 42.

Extending through each pair of aligned openings 49;49a is a clamping jaw'pivot pin 83. Each pin'83 has a head 84 "at one end'received'in one of. the counterbored sockets'50; At the outer end of each pin 83 is a reduced'screw' threaded portion 85 screwed into the'reduced screw threaded portion of thethrough opening 49a. The'screws' to thereby space arms 48f-rom oneanother; Each clamping jaw88 is in the-form of a-lever-having an intermediatesleeve portion- 83fo'rmed with a through opening through which the'pivot pin 83 passes; It will be' noted that each pin 83 traverses thespace 5| and-each 'clampin'g jaw 88 is received between a pair of arms=48 and on the pivot pin 83;

Attached to the forward end of each'rim cover 11 by means of screws I25 is a spring wiping plate I26 extending downwardly and contacting the lever. The wiping plate I26 serves" to exclude dirt from thechuck;

Extending forwardly from each sleeve portion l 89 is an arm 92 having at its outer end, 'a somewhat enlarged rounded head 93. Extending forwardly from each'sleeve 89' is a projection 93a from which extends downwardly I a jaw 94 formed'at its lower end with a plurality of 'teeth' or serrations 95. Serrations 95*are arranged along an arcuate curve. The spacesbetweenthe teeth are inclined forwardly and towards the axis of the chuck body. 'I'heouter edges of the teeth lie on a conical surface, the axis of which ing the surface 39. of the slot.. Each cam.fur.-. thermorehas at its inner surface a rearwardly' and inwardly tapered flat surface I 0521' Thesurfaces I05 of the three cams are 'tangent' to a common cone coaxial with the chuck body. Each cam is furthermore provided at'its outer end with a forwardly extending jaw I06 formed with a transverse slot I01 having tapering transverse surfaces I08 inclined rearwardly -and toward:

Each

each-;.other;. ;Th e rearl heads-LBSloLtheicIamping jaws 18 .are' received; in. the slots. I 0.1.. J. Each card islurthernioreformed with alradial socket. or;

opening] III. in which: is slidably fitted :a;cyline. dri'cal' springmousing I II.closediatLitsiouter end. Withinv each housing III' is alcoilcdmpression spring 1| I2v normally. urging 'the spring: housing radially. outwardly toward theinner SlllfflJCB'lOfi.

therecessBI.ofitherim'cover 1.1;: J: 1 .-:Means is provided to move the cams I rato theiforwa'rd Iend Jdraw bar I3. an. axial operatinglco'ne I.I3.-1:The operating cone sl l3 i's: disposed within the through op'ening 3I "ofithe .of each web I39 and-between each pair of arms I I communicates with the outer end of each chuck body. It islf'ormediwith an axial through.

opening I I 4 countersunk at .its 1 forward end as atlfl I55 Extending through the-opening II I- is.

a-b0lt LI I6 the rear-end of which is T screwed as at I'I'I to the forward end of thezdraw bai xA dial opening I 5I in which Isa spring housing spacer II8 surrounds the .bolt II6- and is interposed between thei draw-bar and-the -operating cone.' 'I'he' cone I I3 is :formed 'with three equi angularly spaced similarslots II.9 toreceive the inner ends of the three respectivelycams I00. Each slot Ii-comprises a flat ta-. pered surface I20' and parallel side surfaces I2I. The surfacesiI20=are complementary to the surfaces I05 of. the cams. .The cone: I I3 mayslide axially within the opening 23L .As the draw bar I3- pulls'. the .cone-I.I3..to the left, looking pivot..pins;.83. .1. ill) 5.1; The .work piece W, which is shown. or

the purpose of illustration in the form of .a gear blank, has'an inneraconicalsurface I25 which.

tapers. inwardly: and -re'arwardly. This tapered surface I25is" gripped by the teeth n15 of the back jaws. I2. -Eachwork piecefurther com- I prises can outer. forwardlyand inwardly tapering conical surface 1.I2B,. and .this surface I is. gripped by.:the teeth 95 of the clamping jaws.

Thusrasxthe. cams I00 .move radially outwardly, therclamping .jaws are swung about-their pivots spindle as by bolts.I3I4 and fitting onto. the spin-fi dle inf the conventional manner; ..."l'he. ;body.v I33 1 is formed with. an axial opening I35 extend-.3 ing to the rear en'd thereof; The forward end 5 of-thetube I32 is screwed into the rear end of I36 which 1 communicate with theiaxial opening 5' through I the radial opening; I31 Within each b'ore I36 10 'is a p'iston I38; r dially.outwardly;= 'rToLthis end there is attached 1 bore'-I-36-.- Covering"each space I42 of bore I36 is a rim cover 'I5Il fixed in any suitable man- I52 pushed outwardly by-acoil comp spring- I53,--against the rim cover I50. 1

- Pivoted oneach pin I is a clamping-jaw" 88 similarto that-described hereinabove. Each withina slot I56 in ones-of the 5 jaw- '80-engages cylinders; v I

When hydraulic medium is pumped from alve Each cylinder I36 is formed with a"ra-' I3I through the adapter I30, through tubeI3-2 and opening I35 and passages I31 to the inner '30 ends; of bores I36, the'pistons 'l38'will be movedradially outwardly to swing the jaws -88 clamping engagement with the workpiece W pressing the workpiece against the back 12, similar to the jaws shown in-Fig. 1;

The advantage of such construction" i ws.

" that eaohcylinder I33 may move independently'of the other, so as to take care of eccentricwork pieces; Thus one cylinder may move outwardly to a i greater extentthan the other. 'When the valve 0-I3I relieves the hydraulic pressure, the springs I53 move the cylinders I38 radially inwardly to relieve the work piece.

It will thus be seen that there is provided a device in which the several objects of this inven- =tion are achievedand which is well adapted t andthe. teeth .95 exert force on the work piece.

radiallyand laterally. at'the same time, thereby enabling the work piece to be clamped across solid metal rather than exerting the total of the clamping force across the diameter" of the work piece, and thereby eliminating distortion.

Itwill be noted that the back jaw 'I2.takes the thrust of the lateral clamping force. The serrations or .teeth on the back jawsas, well as theclamping jaws act to clamp the work piece as, well-as to rotate the work piece. Whenthe drawbar I3 is moved to the right, looking at Fig. 1, the springs II2 will move the cams I00 radially inwardly. to swing the clamping jaws out of engagement with respect to the work piece.

In Fig. 6 there is shown a lathe spindle I0 and a chucking device Ila embodying the invention and illustrating a modified construction. The chucking device I la has hydraulic means for independently rotating each of the clamp.- ingjaws 88. Attached to the rear end of the spindle I0, is an adapter I30 and mounted on the rear end of the adapter I30 is a non-rotating conventional valve I3 I. Extending through the spindle is a tube I32 which communicates *The'chucking' device Ila comprises a chuck body-I33 attached to the forward end of the meet the conditions of practical use. 7 I I As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiment above set .forth, it is tobe understood that all matter herein;

setlforth or shown in the acompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention I 5 .new and, desire to secure by Letters Patent:

device comprising a chuck body, a plurality of radially moving members on the chuck body,

0 levers pivoted to said chuck body and engaging 1. A chucking device adapted to be atta ched to the nose of a spindle of a lathe, said chucking c me said radialmembers, means to move thejradial. members radiall to rotate said levers and said levers having jaws adapted to engage an annular work piece for chucking the same, and back jaws fixed to the chuck body whereby the work piece may be pressed by' the levers against said "back jaws, said back jaws being formed with teeth to grip said work piece'and saidlever jaws havin'g forwardly and inwardly inclined teeth.

to the'nose of -a spindle of a lathe, said chucking 2. A chucking. device adapted to be attached devicecomprising a chuck body, a plurality of said radial members, means to move the radial membersxradially totirotate :said levers; and 1 said levers havingl means'adapted to engage an an nulanwork'piece'for. chucking the same, and'ba'ck I jaws fixed to' the chuck'body whereby the work piece may be pressed by the levers againstsaid back-jawasaid back jawsbeing'formed withteeth to grip said work piece, saidlevers beingformed with teeth" to grip said work piece. Y

3. A chucking device for a lathe comprising a chuck body, means to attach the chuck body td-the nose of a lathe spindle,'said chuck body being formed with a plurality of radial slots, a cam ineach slot, a central cone member adapted to be moved axially for moving the cam members-- radially outwardly, leverspivoted to the chuck bodyabout axes tangent to a common circle, each lever having an arm in engagementwith oneof: the cam members, and spring means to-move the-- cammembers radially inwardly.-

4. Achucking device comprising a chuck-body, aplurality of radial members on the chuck-bodyv totheaxis of. thezchuck body a lever for each radial: member, each-lever being-pivoted abouta pivotperpendicular to and spaced from the axis of the body, each lever. having arearwardly ex-. tending arm engaging-one of said radial members and each lever having-a forwardlyand inwardly extending portion provided with. gripping teeth,v

said gripping-teethbeing disposed ona conical surface coaxial with the chuck-body-andbeinginclined forwardly and inwardly, and arcuate back jaws fixed to-said chuck body and having grippinglteeth inclined outwardl and forwardly.

6. 'A chucking.devicecomprising a chuck body, means .to attach thechuck body to the nose of alathe spindle, said chuck body beingformed with-a pluralityof. radial slots'and with a pair of spaced forwardly-extending arms .on opposite sides of each slot, each'pair of arms being formed with .aligned openings, -a pivot pin passing through said-aligned openings and .interconnecting said arms, a lever pivoted to each pivot pin and disposed between said pair of arms, a cam member slidably mounted within each radial slot, means on each cam and lever to cause the lever tobe rotated about itspivot pin upon moving said cam radially outwardly, means on said levers to exert pressureon an annular work piece in directions inclinedrearwardly and towards the axis of theehuck body, upon beingv rotated by outward movement of said radial members, and means catthercenter of. the chuck body to move said radial members outwardly.

'7. Aehucking device comprising a chuck body,

means to attach the chuck body to the nose of a lathe spindle, said chuck body being formed with a plurality of radial slots and with a'pairofspaced" forwardly extending arms on opposite. sides of each slot,each pair -of arms be-' ingsformed withralignedopeningsya pivot pin passing through saicl aligned-openings. and in.-

terconnecting-isaid armsp a lever pivoted to each.

pivot pin'anddisposed between said pair'of arms,

a-cam member slidably mountedwithin each' radial slot, means on each cam and lever.:to. '1 cause the lever to be rotated about its pivot pin upon moving said cam. radially outwardly;-

means .on said levers to exert pressure on-an annular work piece in directions inclined rearwardly and towards the axis of the chuck'body, upon being rotated by outward movementof said radial members, and means at the center of the chuck body to move said radial membersoutwardly, a cover plate attached to eachpair of arms and covering one of the slots and over-- lying the radialmember therein, and thei lever on the pivot pin supported by said pair of arms,

spring. means interposed-between each radial member and the cam member associated therewith for urging the radial member toward'the:

axis of the chuck body.

8. A chucking device compising a chuck body,

means to. attach the chuck body to the nose of.

a lathe spindle, said chuck-body being-formed with, a pluralitywof radial slots and with a pair of spaced forwardly extending arms on opposite sides of each slot, each pair of arms being formed with aligned openings, a pivot pin passing through said'alignBd openings and interconnecting-said-arms, a lever pivoted to each-pivot pin and disposed between said pair ofsarms, a.

calm member slidably mounted within each 'ra-' dial slot, means on each cam and lever to cause the lever to'be rotated about its. pivot pin'upon moving said cam radially outwardly, means on said levers to exert pressure on an annularwork piece in directions inclined rearwardly-and towards the axis offi'the chuck body, upon-being rotated by outward movement of said radial members, and means at the center of the chuck body to move said radial membersoutwardly, a cover plate-attached to each pair of arms and covering one of the slots and overlying the radial member therein, and 'thelever on the pivot pin supported by said pair of arms, spring means interposed between each radial member and the cam member. associated therewith for urging the. radial member toward the axis of the chuck body, and-a wiping plate attached to each cover' member and 'having' wiping engagement the lever associated .therewith.

9. A chucking device comprising a chuck body, means-to attach the. chuck'body to the'nose' 01' a lathespindle, saidchuck'body being formed with a. plurality ofradi'al slotsand with a pair ;oi'spaced forwardly extending arms on'opposite sides oi each' slot, each pair of arms being formed with aligned openings, a pivot pin-passing through said aligned openings and interwith connecting said arms, a lever pivoted to each pivot pin and disposed between said pairof arms, a cam member slidably mounted within each radial slot, means' on each cam and lever to cause the-lever to be rotated about its pivot pin upon moving said cam radially outwardly, means on said leversv to exert pressure on an annular work piece indirections inclined rearwardly and towards the axis of the chuck'body, upon being rotated by outward movement of said radial membersyand means at thecenter of 'the' chuck body to move said radial members outwardly, a cover'plate attached to each 'pair of arms and 'coveringone'of the'slots and-overlying the radial member therein, and the lever on the pivot pin'supportedbysaid pairof arms, spring means -interposed between each'radial member and the cam member associated therewith for urging the radial member toward the axis of the chuck body, and a wiping plate attached to each cover member and having wiping engagement with the lever associated therewith, and back jaws fixed to the chuck body whereby the work piece may be pressed by the levers against said back Jaws.

10. A chucking device comprising a chuck body, means to attach the chuck body to the nose of a lathe spindle, said chuck body being formed with a plurality of radial slots and with a pair of spaced forwardly extending arms on opposite sides of each slot, each pair of arms being formed with aligned openings, a pivot pin passing through said aligned openings and. interconnecting said arms, a lever pivoted to each pivot pin and disposed between said pair of arms, a cam member slidably mounted within each radial slot, means on each cam and lever to cause the lever to be rotated about its pivot pin upon moving said cam radially outwardly, means on said levers to exert pressure on an annular work piece in directions inclined rearwardly and towards the axis of the chuck body, upon being rotated by outward movement of said radial members, and means at the center of the chuck body to move said radial members outwardly, a cover plate attached to each pair of arms and covering one of the slots and overlying the radial member therein, and the lever on the pivot pin supported by said pair of arms, spring means interposed between each radial member and the cam member associated therewith for urging the radial member toward the axis of the chuck body, and means on said pivot pins to space said arms to provide proper clearance for the levers.

11. A chucking device for chucking annular work pieces, said chucking device comprising a chuck body adapted to be attached to the nose of a lathe spindle, a plurality of fixed back jaws on said body, said back jaws being curved and lying in a common circle coaxial with the body, a plurality of levers pivoted to the chuck body about axes tangent to a common circle coaxial with the body, means to simultaneously rotate said levers, said levers having at their forward ends curved jaws lying in a common circle coaxial with the body, and formed with gripping teeth inclined forwardly and towards the axis of the body. v

12. A chucking device comprising a chuck body adapted to be attached to the nose of a lathe spindle, a plurality of levers pivoted to the body about axes tangent to a common circle coaxial with said body, each of said levers having a rearwardly extending arm and a forwardly extending arm, the forwardly extending arms of said levers having jaws offset inwardly toward the axis of the body and formed with curved gripping means inclined forwardly and towards the axis of the body and disposed on a common circle of smaller diameter than the circle to which the lever axes are tangent, and a plurality of back jaws fixed to the body and disposed rearwardly of the levered jaws, said back jaws being curved and lying in a common circle coaxial with the body and of a diameter less than the diameter of the levered jaws, and means engaging the rearwardly extending arms of said levers for swinging the levers to move the gripping jaws on the levers simultaneously toward the axis of the body and toward the back jaws, for chucking an annular work piece between the levered jaws and the back jaws.

MAX 0. TRUDEAU.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Germany Apr. 24, 1914 

